Automatic firearm



Feb. 7, 1939.

V. HQLEK AUTO'MATIC FIREARM Filed July 28, 1936 LZZ/ Patented Feb. 7, 1939 UNITED STATES 2,146,185 AUTOMATIC FIREARM Vaclav Holek, Brunn, Czechoslovakia, assignor to Ceskoslovenska Zbrojovka a. s. Brunn, Brunn,

Czechoslovakia Application July 28, 1936, Serial No. 92,981 In Czechoslovakia September 5, 1935 Y 6 Claims.

The present invention relates to an automatic firearm and has for its object increased stability as compared with previously known automatic firearms, especially when the firearm is mounted on a gun-carriage or on a stand, and consequently an increased accuracy of fire. This object is achieved according to the present invention by making full use of early firing for damping the reaction forces which act upon the mechanism of the firearm and upon the stand or support during firing.

By early firing is meant the firing of the cartridge at the moment when the sliding masses of the firearm are in the course of their forward movement and have not yet reached their forward turning point.

The present invention employs early firing in a firearm of the kind in which the energy of the recoil together with the energy of the expanding gases, which are produced in the barrel on discharging the firearm, make use of two mechanisms of the firearm for their absorption, namely the sliding barrel on the one hand and the gas piston mechanism or other gas motor, which drives the whole operating mechanism of the firearm, on the other hand. By the combined use of these two mechanisms of the firearm and of early firing the desired results, namely the stability of the gun and accuracy of fire, are attained.

The use of early firing is already known in connection with firearms having a fixed barrel and with firearms having a rearwardly slidable barrel.

In the case of firearms having a fixed barrel in which a moving breech block is used, the early firing has to be efiected within a short interval of time, in order that sufficient energy should be left for effecting the rearwardmovement of the breech block mechanism and for the carrying out of the necessary operations connected therewith before the shot leaves the barrel. Only after this has happened, the forces acting upon the gun carriage may be damped, which with regard to the braking in the course of the short path of travel can only imperfectly be attained. In this way, much of the accuracy of the firearm is lost.

In the case of firearms with a movable barrel, which for the most part operate with a locked breech, the movement of the cartridge feed mechanism as well as that of the bolt or breech block is derived from the movement of the barrel. With these firearms also, early firing must likewise take place over what is relatively a very short path of travel and in a short interval of time, and it is impossible to make use of the kinetic energy of the sliding masses for damping the forces transmitted to the gun carriage, since this energy is absolutely necessary for the actuation not only of the breech block, but of the cartridge feed mechanism also. In this case the damping influence of the forces is in practice verylittle and consequently early firing is not used in such firearms. Moreover, even if the shot is fired while the sliding masses are still moving forward, the resulting reaction is transmitted to the firearm by means of the recuperator spring, which reduces the precision of the firearm.

These disadvantages are removed according to the present invention in that the firearm, in which the firing of the cartridge takes place during the return i. e. the forward movement of the barrel, which follows the rearward movement following the firing before the front turning point is reached, is provided with a movable barrel which absorbs part of the energy of the recoil during firing and with a motor which makes use of the gas expansion in the barrel for driving the operating parts of the firearm, such as the breech-block and cartridge feed mechanism,

The motor, .which advantageously has the form of a gas piston mechanism, thus operates completely independently of the movement of the barrel and serves for actuating the breech-block mechanism and/or the cartridge feed mechanism, Whilst the movable barrel, which reciprocates between the early firing 'and the relatively weak forwardly acting spring, brings about the damping of the reaction forces.

Due to the early firing, in accordance with the law of the maintenance of the centre of mass, an alteration takes place in the direction of movement of the barrel from plus to minus, whereby the energy stored in the forwardly moving barrel is consumed and the barrel then has a reduced rearward energy, so that it then carries out only a small movement against the force of the return spring. The return spring is a detrimental element whichtransmits the force to the gun carriage. In the firearm according to the present invention only a very small amount of work is left for the return spring to perform, so that the spring may be a weak one and, its effect upon the gun carriage negligible.

In the firearm according to the present invention, full use is made of the early firing for damping the forces acting upon the gun carriage in both directions, since it operates over a long distance for a considerable period of time, so that the force resulting from the kinetic energy and its effect upon the gun carriage in the forward direction is small. I An appreciable part of the energy ofrecoil is consumed during the early firing, so that the sliding movement of the barrel is moderate and is completed in quite a short distance; thus a weak return spring suifices for the absorption of the remaining enthe barrel arrangement of the firearm according to the present invention, namely that, with the combination of the early firing with the sliding barrel andv the gas piston mechanism, the gas piston mechanism, that is to say the gas cylinder and the gas piston, operate as a dashpot and effect further elastic damping of the movement of the barrel. Due to the use of the arrangement according to the present invention and further taking into account the dashpot effect, the barrel performs a reciprocating movement about its mid position, the extent of which movement is determined merely energetically in both directions. The outer turning points, thus defined, of the oscillating system ofmasses are sumciently removed from the rigid stops arranged in the firearm so as to prevent shock from meeting a hard surface, which give rise to great forces and is detrimental to the stability and accuracy of the firearm.

In particular, the arrangement according to the present invention can be made use of when shooting with ammunition ofdifierent explosive pressures without any disadvantages making themselves felt. a-

The subject of the present invention is illustrated by way of example in the accompanying drawing in which,

Fig. 1 shows a longitudinal section of the firearm and the gas piston mechanism. The position of the mechanism is that'obtaining at the moment after the first shot has been fired.

Fig. 2 shows a portion of the same section of the firearm with the operating mechanism in another position, and

Fig. 3 illustrates diagrammatically the course of the movement of the sliding masses of the firearm inits various phases.

I is an air-cooled barrel mounted longitudinally in the casing'2 of the firearm. The muzzle of the barrel is provided withv a vent 3 which communicates with the gas cylinder 4. The gas cylinder is secured to the barrel I. At the breech end of the barrel is rigidly attached and guided in the casing 2, a casing 8 for the breech block 9, in which the firing pin I8 is accommodated in known manner. The breech-block 9 is supported and controlled by the carrier I0, the forward extension of which forms the rod II which ends in the gaspiston I2. Only the gas piston I2 there fore is mounted in the gas cylinder 4. The breech block carrier I0 is loaded by the return spring I4 one end of which presses against the rear wall of the firearm casing 2. The carries I0 is provided with the projection I! which depending on its position relative to the breech-block 9- actuates, by a rear cam face, the breech-block mechanism and by a front cam face the firing pin I8. The barrel I is loaded by the spring I5 which is mounted in the two part housing 18. The frontthe-barrel. 'The upper end .of the part 20 cooperates with the projection 22 on the barrel, and the part 20 itself is moved in one direction by the inclined projection 28 on the rodII and C breech in a known manner.

In the other direction by the spring 2I The firearm is mounted by means of the bearing 25 upon the pivot pin 26 of the stand 21.

The releasing device arranged in the casing 2 of the firearm comprises the trigger 28 and the double-armed lever 29, one arm of which is pressed against the trigger 28 by the spring 30, while its other arm cooperates with the projection 3| formed on the breech block carrier ID. The cartridges are arranged on a band which is conveyed stepwise by a feed device which may be of any known construction and may comprise a movable plate 32 and pawls actuated by a lever mechanism in dependency from the carrier I0 so that the energy of rearward movement of the breech-block carrier is transferred to this plate.

The actionof the firearm is as follows:

After the first shot has'been fired the firearm system, comprising the barrel I, the casing 8, the breech block 9, the carrier III, the rod II and the piston I2, moves rearwardly as a whole under the influence of the expanding gases, whereby the return spring I5 is compressed. As soon as the projectile has passed over the vent 3 in the barrel, the breech block carrier I0, due to the action of the gas pressure in the gas cylinder 4 upon the piston I2, begins to move rearwardly with greater speed than the barrel I. During this movement the unlocking of the breech of the barrel and the ejection of the empty cartridge take place in any known manner, for instance by the rear cam face of the projection IT unlocking the breech 9 which may be arranged to be free, at this stage, for swinging movement or for rotation within the casing 8. The path of the breech-block carrier I 0 and of the breech-block 9, which form together the breech-block mechanism proper, is considerably longer than the path of the barrel I with the casing 8. The movement of the carrier I0 proceeds counter to the action of return spring I4 and is limited by a stop on the rear wall of the casing 2. During this movement of the carrier the empty cartridge case is withdrawn from the cartridge chamber and ejected from the firearm by an ejector of any known construction. After reaching the rear turning point, firstly, under the action of the spring I5, the barrel I with the breech block casing 8 and secondly, under the action of the spring I4, the carrier I0 with-the breech block 9 after traversing unequal paths of movement return forward oncemore independently of one another. This movement of the barrel I is interrupted by the projection 22 onthe barrel engaging with the upper end of the member 20, which has moved into the path of this projection during the rearward movement of the carrier I 0 (Fig. 2). The carrier I0, however is meanwhile driven forward together with the breech block 8, accelerated bythe spring I4, and during this movementthe' breech block. slides a new cartridge into the firing chamber of -the barrel and closes the Shortly thereafter the projection 23 on the still forward moving piston rod displaces the part 20 againstlthe action of the spring-2| (Fig. 2) and thereby frees the barrel for continuing its interrupted forward movement which takes place under the action of the spring I5.

Immediately afterwards the projection I1 strikes against the firing pin I8 4 and the shot is discharged, since the carrier I 0 moves forward with greater speed than the barrel I does. 1

The rearward reaction of the expanding gases which occurs when a new shot is fired is almost completely compensated by the kinetic energy of the system of masses, which are thus prevented from striking the rigidfront stop, and a small part only of the recoil energy brings the barrel back against the altogether negligible force of the springs 14, 55, which are only strong enough to return the barrel before it strikes the rigid rear stop. The breech block .mechanism 9, Hi meanwhile receives a new impulse from the gas pressure in the gas cylinder and consequently repeats the movements already described.

Fig. 3 represents schematically the successive positions occupied by the barrel and the movable parts associated therewith, in the course of a number of successive discharges during automatic operation of the firearm. A1, A2 are fixed abutments arranged in the casing of the firearm which limit the maximum reciprocating movements of the system of masses. M1 represents the mass of the barrel I together with the parts 4, 8 connected therewith, whilst M2 represents the mass of the breech block mechanism 9, Ill, H, [2. The perpendicular lines U1, U2 represent the turning points of the reciprocating movements of the barrel, U1 being the front and U2 the rear turning point. The position I represents the position of the operating mechanism of the firearm when firing is commenced. The position 11 represents the rear turning point of the barrel in the series of operations performed in the firing of the first shot. The breech block mechanism 9, l since it traverses a longer path of movement, does not at this moment form a unitary system with the barrel I. The position III represents the moment when the whole system of masses I, 4, 8, 9, II), II, I! is released as a whole by the sear member for forward movement during which movement over the distance Z the shot leaves the barrel. The barrel together with its associated parts meanwhile continues to move forward until it reaches the front turning point U1. at position IV. The subsequent end positions occupied by the barrel during further automatic action of the firearm are represented at V, VI,--V]I and VIII. The intermediate positions corresponding to position III occupied by the moving parts during such 'further automatic action are omitted from the figure for the sake of simplicity.'-

tinuous fire, after the first shot has been discharged, the stops or movable system of masses reciprocates between two fixed points A1, A2. whilst the turning points U1 and U2 of the reciprocating movement of the system lie at a safe distance from the fixed points. In this manner a smoothreciprocation movement is ensured during shooting even in the event of a delayed discharge or violent reaction impulses. v

The firearm ill'ustrated in the drawing is only a constructional example and details thereof can be altered without-thereby affecting the principle of the present invention.

1. An a "tomatic firearm comprising in combination; a casing, a slidable'barrel, a gas motor fixed to said barrel and a breech arranged to be operated by said gas'motor, all reciprocally mounted in said casing so as to be moved rearward by the recoil force of an exploding cartridge, spring means arranged to move said'parts forward and means for firing a cartridge while said barrel is in the course of its forward movement.

2. An automatic firearm comprising in combination, a casing, a slidable barrel, a gas motor fixed to said barrel and a breech, all reciprocally mounted in saidcasing so as to be moved rearward by the recoil force'of an exploding cartridge, spring means arranged to move said parts forward, means for locking said breech, arranged to be operated by said gas motor, and means for firing a cartridge, while said barrel is in the course of its forward movement.

3. An automatic firearm comprising in combination, a casing, a slidable barrel,,,a gas motor fixed to said barrel and comprising a gas cylinder fixed to and communicating with the boring of said barrel and a piston reciprocable in said cylinder so as to be actuated by the gas developed by the explosion of a cartridge and a breech arranged to be operated by said gas motor, all reciprocally mounted in said casing so as to be moved rearward by the recoil force of an exploding cartridge, a cartridge feed mechanism, spring means arranged to move said barrel, breech and cylinder forward, spring means arranged to independently move said piston forward, and means for firing a cartridge, while said barrel is in the course of its forward movement.

4. An automatic firearm comprising in combination, a casing, a slidable barrel, a gas motor fixed to said barrel and comprising a gas cylinder fixed to and communicating with the boring of said barrel and a piston reciprocable in said cylinder so as to be actuated by the gas ,developed by the explosion of a cartridge and a breech, all reciprocally mounted in said casing so as to be moved rearward by the recoil force of an exploding cartridge, a cartridge feed'mechanism, said motor being arranged for operating said cartridge feed mechanism, spring means arranged to move forward said barrel, breech and cylinder and, independently thereof, said piston, and means controlled by said gas motor for firing a cartridge while said barrel is in the course of its forward movement. 5. An automatic firearm comprising in combination, a casing, a slidable barrel, a gas motor fixed to said-barrel, said motor comprising a gas cylinder fixed to and communicating with the boring of said barrel and a piston reciproca- It is clear from the figure, that. during conoperating said breech and said cartridge feed -mechanism, spring means arranged to move forward said barrel, breech and cylinder and,

independently thereof, said piston, means con'' trolled by said gas motor for firing a cartridge while said barrel is in the course 'of its forward movement, and meansmonnected with said m0- tor piston for controlling the discharge of the cartridges during the forward movement of said barrel.

6. The firearm of claim 3, in which a member serving to control themoment of firing is mounted in the casingbetween the rod of said piston and the-movable barrel, so as to temporarfly stop the returnmovement of said, barrel.

vAcLAv'noLEK. 

